docs: def load_engine_and_libs(matlab_root, options):
      """Load and return `libeng` and `libmx`.  Start and return MATLAB
      engine.
  
      Returns
      -------
      engine
      libeng
      libmx
  
      """
      if sys.maxsize > 2**32:
          bits = '64bit'
      else:
          bits = '32bit'
  
      system = platform.system()
  
      if system == 'Linux':
          if bits == '64bit':
              lib_dir = join(matlab_root, "bin", "glnxa64")
          else:
              lib_dir = join(matlab_root, "bin", "glnx86")
  
          check_python_matlab_architecture(bits, lib_dir)
  
          libeng = Library(
              join(lib_dir, 'libeng.so')
          )
          libmx = Library(
              join(lib_dir, 'libmx.so')
          )
  
          command = "{executable} {options}".format(
              executable=join(matlab_root, 'bin', 'matlab'),
              options=options
          )
  
          ### Check for /bin/csh
          if not os.path.exists("/bin/csh"):
              warnings.warn("MATLAB engine requires /bin/csh.  Please install it on your system or matlab_wrapper will not work properly.")
  
      elif system == 'Windows':
          if bits == '64bit':
              lib_dir = join(matlab_root, "bin", "win64")
          else:
              lib_dir = join(matlab_root, "bin", "win32")
  
          check_python_matlab_architecture(bits, lib_dir)
  
          ## We need to modify PATH, to find MATLAB libs
          if lib_dir not in os.environ['PATH']:
              os.environ['PATH'] = lib_dir + ';' + os.environ['PATH']
  
          libeng = Library('libeng')
          libmx = Library('libmx')
  
          command = None
  
      elif system == 'Darwin':
          if bits == '64bit':
              lib_dir = join(matlab_root, "bin", "maci64")
          else:
              unsupported_platform(system, bits)
  
          check_python_matlab_architecture(bits, lib_dir)
  
          libeng = Library(
              join(lib_dir, 'libeng.dylib')
          )
          libmx = Library(
              join(lib_dir, 'libmx.dylib')
          )
  
          command = "{executable} {options}".format(
              executable=join(matlab_root, 'bin', 'matlab'),
              options=options
          )
  
      else:
          unsupported_platform(system, bits)
  
      ### Check MATLAB version
      try:
          version_str = c_char_p.in_dll(libeng, "libeng_version").value
          version = tuple([int(v) for v in version_str.split('.')[:2]])
  
      except ValueError:
          warnings.warn("Unable to identify MATLAB (libeng) version.")
          version = None
  
      if (system == 'Linux') and (version == (8, 3)) and (bits == '64bit'):
          warnings.warn("You are using MATLAB version 8.3 (R2014a) on Linux, which appears to have a bug in engGetVariable().  You will only be able to use arrays of type double.")
  
      elif (system == 'Darwin') and (version == (8, 3)) and (bits == '64bit'):
          warnings.warn("You are using MATLAB version 8.3 (R2014a) on OS X, which appears to have a bug in engGetVariable().  You will only be able to use arrays of type double.")
  
      ### Start the engine
      engine = libeng.engOpen(command)
  
      return engine, libeng, libmx, version